Spurting noises in Theta TLC (jitter attenuator)

[arupg]

I have a Theta TLC that's a jitter attenuator. When the transport's disc tray is either opened or closed after changing discs, there's a small spurt of a noise that is heard from the speakers.

When the disc tray is opened or closed, the DAC doesn't lose its LOCK condition though. The LOCK on the dac is ON moment the units are powered on.

Connection : Transport - - - > Theta TLC - - - > DAC (all sPDIF Coax)

Attached is the PCB of the Theta. There are several Tantalum caps in there, some in PSU, some as bypass and some on digital signal.

Could these or one of them be the culprit? What's a good modern day substitute for them if all of them were to be replaced? The values in there are 0.1uF, 1uF & 100uF. The entire circuit works at 6V or below.

Advice / suggestions will be most appreciated.

Thanks in advance!

[arupg]

Here's the PCB